i just used a half can of black paint on my mk2 header. didnt prime the metal tho, didnt think it needed it. have had the header on the car for over a month, and i did the on-car paint bake method too, because mom would have shart a BUICK if i would have been cooking a header in her $$$ gas over...
even having to cure it on the car was NOT BAD tho.. its been holding up GREAT. and i have been TRYING to get the paint to burn off the manifold, or first couple inches of the header tubes maybe, but its doing GREAT.. not even discolored..
i had painted a mk1 header with some BBQ paint (what a joke) and tried to cure it on the car too.. needless to say, almost every spec of that paint flaked off the header, and i was left with bare, clean metal after that.. there was a LITTLE paint left on the collector, but not much.
basically, this is some of the best header paint i have personally ever used.. its called VHT for a reason (VERY HIGH TEMP)
it has silica, and ceramic suspended in the paint also..
but for ~$10 a can, it better work pretty darn good!